Sugarcane resistance to the sugarcane borer: Response to infestation among progeny derived from resistant and susceptible parents

摘要

The sugarcane borer (SCB), Diatraea saccharalis (F.), is the most important insect pest of sugarcane (Saccharum spp.) in Louisiana. The deployment of SCB-resistant cultivars is an integral part of the integrated pest management approach to minimizinginjury from SCB infestation. Our objective was to evaluate the response to infestation among sugarcane progeny derived from SCB resistant (R) and susceptible (S) parents. SCB resistance was measured, as percent borer-damaged internodes, among progeny from 13 bi-parental crosses in the plant-cane (1998) and first-ratoon cane (1999) crop years and the Best Linear Unbiased Prediction (BLUP) effect for each cross was estimated. Significant BLUP estimates (i.e., BLUP < 0 at the 0.05 level) were found for thesame set of crosses in both crop years. These crosses had at least one resistant parent whereas none of the S x S crosses could be categorized as resistant. Results as to whether the resistant parent should be used as a male or female were inconsistentprobably reflecting the complex contribution and interaction of several mechanisms that govern resistance of sugarcane to the SCB. Progeny mean BLUP estimates in the two crop years were highly correlated despite the large disparity in the level of borerinfestation in the 2 crop years (Mean: 20.4% in 1998 and 6.4% in 1999). In both crop years, the genetic variation and genetic coefficient of variation among crosses were smaller compared with those within crosses. These results indicate that, population-wide SCB resistance could be reliably increased by diligently selecting and crossing among the most resistant parents and then focusing selection on progeny within those crosses.